SPINAL DISC AND MOTION PRESERVING IMPLANT SYSTEM

Abstract

 An orthopedic implant system is disclosed for use in correcting or reducing the progression of scoliosis. The orthopedic implant system can be inserted laterally or posteriorly and comprises an elongated flexible member secured to a user's spinal column via a plurality of vertebral body screws. Typically, the width of the elongated flexible member is significantly wider than the height, creating a flattened cross-sectional aspect. The vertebral body screws comprise a screw head with a slot sized to accept the elongated flexible member, or a slot and space sized to accept an insert, and a screw base. Typically, the elongated flexible member is positioned within the slot and space via an insert, and is allowed to slide within the screw head or insert as needed, as the user moves. However, at the apex of the user's scoliosis curve, the elongated flexible member is fixed within a vertebral body screw head.

Description

BACKGROUND

[0001] Currently, operative methods for treating spinal deformities, such as scoliosis, include correction of the spinal curvature via some form of internal fixation device, and immobilization of the spine in the corrected state. Typically, the internal fixation device includes an implantable rod or a pair of implantable rods for mounting on either side of the posterior aspect of the spinal column. When a pair of implantable rods are used rigid transverse bars are often used to connect the rods together in spaced-apart parallel arrangement. Anchors in the form of hooks or screws are provided along each rod for anchoring the same to selected vertebrae. Once installed, the anchors are rigidly locked to the associated rod to prevent relative motion there between. Further, the arrangement may be supplemented with bone grafts and the fusion of several vertebrae in order to prevent the apparatus from breaking due to the load induced thereon. However, immobilization of the spine results in physical restrictions in movement and may cause complications throughout the patient's life. Typically, present technology for scoliosis systems immobilizes the spinal column, may not preserve a user's spinal discs, and results in physical restrictions for life that may also result in psychological issues. Thus, an effective solution is necessary.

[0002] The present invention allows a significant degree of motion in most plains while the implants are in place and unrestricted freedom of movement should the implants be removed. The flat shape of the elongated flexible member (or band) allows a user to flex, extend, or rotate while at the same time restricts lateral bending/movement at the levels of implantation. Thus, the present invention provides resistance in the plain of a scoliotic curve while at the same time allowing movement in other plains. A variation of the present invention provides the ability to correct and/or restrict vertebral rotational misalignment. Thus, the orthopedic implant system corrects scoliotic curves and/or restricts growth of scoliosis curves, while allowing preservation of the user's intervertebral discs, preservation of flexion, extension and rotational motion, the ability to modify the shape and dimensions of the band to vary the flexibility/stiffness in multiple orientations or directions depending on the user, the elimination of posterior muscle disruption, the ability of the user to grow while the disc and motion preserving implant system is in place, and the potential to remove the device after the user reaches skeletal maturity, such that a user can then live a life that does not include an immobilized spine. Thus, the orthopedic implant system benefits anyone with a spinal deformity.

SUMMARY

[0003] The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed innovation. This summary is not an extensive overview, and it is not intended to identify key/critical elements or to delineate the scope thereof. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

[0004] The subject matter disclosed and claimed herein, in one aspect thereof, comprises an orthopedic implant system for use in correcting or inhibiting the progression of a scoliosis curve. The orthopedic implant system comprises an elongated flexible member secured to a user's spinal column via a plurality of vertebral body screws. Typically, the height of the elongated flexible member is significantly greater than the width, creating a flattened cross-sectional aspect. Further, many configurations of the elongated flexible member are possible depending on the degree and direction of control needed including rotational control and/or correction.

[0005] The vertebral body screws comprise a typical screw base with threads and a screw head with a slot sized to accept the elongated flexible member or to accept an insert with a slot sized to accept the elongated flexible member. The vertebral body screws can be either rotational head screws or fixed head screws. Typically, a fixed head screw is used at the apex of the scoliosis curve of the user's spinal column while rotational head screws are used above and below the apex. Typically a locking end cap is used at the apex of the scoliosis curve to lock the band in place to prevent migration of the elongated flexible member. Typically, for the other screw locations, the elongated flexible member is allowed to slide within the screw heads or within an insert in the screw heads as needed, as the user moves. Further, the screw head of the rotational head screws can rotate as needed relative to the screw base, reducing stresses on the screws and the elongated flexible member as the user's spinal column extends, flexes, or rotates.

[0006] Additionally, the orthopedic implant system can be implanted laterally, via an anterior, oblique, or a lateral surgical approach, or posteriorly, depending on the wants and needs of a user. The orthopedic implant system can be designed in multiple configurations, only some of which are shown in this application.

[0007] To the accomplishment of the foregoing and related ends, certain illustrative aspects of the disclosed innovation are described herein in connection with the following description and the annexed drawings. These aspects are indicative, however, of but a few of the various ways in which the principles disclosed herein can be employed and is not intended to include all such aspects and their equivalents. Other advantages and novel features will become apparent from the following detailed description when considered in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008] 

FIG. 1 illustrates a perspective view of the orthopedic implant system secured to a spine in accordance with the disclosed architecture.

FIG. 2A illustrates a perspective view of the orthopedic implant system in accordance with the disclosed architecture.

FIG. 2B illustrates the end on configuration of the simplest form of the elongated flexible member in accordance with the disclosed architecture.

FIG. 3 illustrates an exploded view of the orthopedic implant system secured to a spine in accordance with the disclosed architecture.

FIG. 4A illustrates an exploded view of a rotational head screw with a standard insert and a standard end cap in accordance with the disclosed architecture.

FIG. 4B illustrates an exploded view of a rotational head screw with a locking insert and a locking end cap in accordance with the disclosed architecture.

FIG. 5A illustrates an exploded view of a fixed head screw with a standard insert and a standard end cap in accordance with the disclosed architecture.

FIG. 5B illustrates an exploded view of a fixed head screw with a locking insert and a locking end cap in accordance with the disclosed architecture.

FIG. 6 illustrates a perspective view of a driver for inserting the rotational head screws in accordance with the disclosed architecture.

FIG. 7A illustrates an end view of the band and insert in a rotational head screw in accordance with the disclosed architecture.

FIG. 7B illustrates an end view of the inserts showing multiple configurations of the insert and the band that passes through the insert within the orthopedic implant system in accordance with the disclosed architecture.

FIG. 8A illustrates a section view of a rotational head screw with a standard insert and end cap in accordance with the disclosed architecture.

FIG. 8B illustrates a section view of a rotational head screw with a locking insert and end cap in accordance with the disclosed architecture.

FIG. 8C illustrates a section view of a fixed head screw with a standard insert and end cap in accordance with the disclosed architecture.

FIG. 8D illustrates a section view of a fixed head screw with a locking insert and end cap in accordance with the disclosed architecture.

DESCRIPTION OF PREFERRED EMBODIMENTS

[0009] The innovation is now described with reference to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding thereof. It may be evident, however, that the innovation can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to facilitate a description thereof.

[0010] The present invention allows a significant degree of motion in most planes while the implants are in place and unrestricted freedom of movement should the implants be removed after the user reaches skeletal maturity. The flat shape of the elongated flexible member (or band) allows a user to flex, extend, or rotate while at the same time restricts lateral bending/movement at the levels of the implantation. Thus, the orthopedic implant system provides resistance to the scoliotic curve at the index levels in the coronal/frontal plain while at the same time allowing movement in the sagittal and transverse plains. A variation of the present invention provides the ability to correct and/or restrict vertebral rotational misalignment. Thus the orthopedic implant system corrects and/or restricts the growth of scoliosis curves, while allowing preservation of the user's intervertebral disc, preservation of flexion, extension and rotational movements, the ability to modify the shape of the band to vary the flexibility in multiple orientations or directions depending on the user, and the potential to remove the device after the user reaches skeletal maturity, such that a user may then live a life that does not include an immobilized spine. Thus, the orthopedic implant system benefits anyone with a spinal deformity.

[0011] Referring initially to the drawings, FIGS. 1-3 illustrate the orthopedic implant system 100 for use in correcting or maintaining a scoliosis curve. The orthopedic implant system 100 comprises an elongated flexible member 102 secured to a user's spinal column via a plurality of vertebral body screws 104 (as shown in FIG. 1).

[0012] The surgical approach for the orthopedic implant system may be anterior, lateral, oblique or posterior and the system may be implanted posteriorly (not detailed or shown) or laterally and comprises an elongated flexible member secured to a user's spinal column via a plurality of vertebral body screws. The preferred embodiment is lateral to the spine and the height of the elongated flexible member (side surfaces) 106, is oriented parallel to or in the same plane as the long axis of the screw. For a posterior system (not shown) the screws would be inserted posteriorly and angled as needed to allow sufficient fixation to or in the pedicles and the side surfaces 106 of the elongated flexible member would be oriented in a manner other than parallel to the long axis of the screw body. (system not shown).

[0013] The elongated flexible member 102 comprises opposing sides 106, a top surface 108, a bottom surface 109, a first end 110, and a second end 112. Typically, the height of the elongated flexible member, surface 106, is significantly greater than the width or thickness, surfaces 108/109, creating a flattened cross-sectional aspect. For example, the ratio of height to width (or thickness), surface 106 to surfaces 108/109, can range from approximately 3:1 to approximately 20:1 depending on the needs of the user, the curvature of the spine and the material used. Further, many configurations of the elongated flexible member 102 are possible depending on the degree and direction of control needed, including rotational control of the vertebral bodies of the user's spinal column, and best design to optimize the system's potential and minimize debris generation and potential breakage.

[0014] For example, FIGS 7A-B show some of the end on configurations 110 and/or 112 of the flexible member 102; standard flat sided band 700, a partial I-beam shape 702, a full I-beam shape 704, a cross-sectional I-beam shape 706, a partial barbell shape 708, a full barbell shape 710 or 712, and a cross-sectional barbell shape 714. In addition the elongated flexible member 102, as viewed from the side 106, can include multiple different configurations (not shown) including a straight flat band, a curved band, a stepped band, or a tapered band. Thus, there is a potential to develop elongated flexible members 102 that have different/varying thickness and different cross sectional geometries, and can be tapered or stepped in various dimensions such as thickness, width, etc. Additionally, the elongated flexible member 102 can have additional configurations to optimize system potential and enable varying degrees of response to the need for overall control of a patient's rotational or flexion/extension movements. Further, the ends 110 and/or 112 of the elongated flexible member 102 can extend past an end of the vertebral body screw heads 104 to allow for growth in the spinal column or an extended range of motion.

[0015] The elongated flexible member 102 would generally be constructed of titanium, cobalt chromium and/or stainless steel, etc., though any other suitable material may be used to manufacture the elongated flexible member 102 as is known in the art without affecting the overall concept of the invention.

[0016] While the shape and size of the elongated flexible member 102 may vary greatly depending on the wants and needs of a user, and depending on the severity of a curve of the user's spine (scoliosis curve), the elongated flexible member 102 is approximately between 5 and 25 centimeters in length as measured from a first end 110 to a second end 112, and approximately between 5 and 15 millimeters in height as measured from a top surface 108 to a bottom surface 109, and approximately between 1 and 3 millimeters wide as measured from opposing sides 106.

[0017] Furthermore, the orthopedic implant system 100 comprises a plurality of vertebral body screws 104 which are engageable with the elongated flexible member 102 and which anchor the elongated flexible member 102 to a user's spinal column 118. The vertebral body screws 104 can be any suitable bi-cortical or uni-cortical bone screws as is known in the art, as long as the screws can be inserted into the vertebra of a user's spine and secured. Further, the vertebral body screws 104 could be rotational head screws 116 or fixed head screws 117, depending on the needs of the user. The vertebral body screws 104 would generally be constructed of titanium, cobalt chromium, stainless steel, etc., though any other suitable material may be used to manufacture the vertebral body screws 104 as is known in the art without affecting the overall concept of the invention. Any suitable number of vertebral body screws 104 can be used as is known in the art, and per the user's wants and needs. Further, implant system 100 could be placed on either the convex or concave side of the scoliosis curve or both.

[0018] The vertebral body screws comprise a screw head, with either a slot sized to accept an elongated flexible member or an insert with a slot sized to accept an elongated flexible member, and a screw base. Typically, both rotational head screws 116 and fixed head screws 117 are used to anchor the elongated flexible member 102. Although fixed head and rotational head screws and locking and non-locking inserts and end caps may be used interchangeably as determined by the surgeon, in a typical construct, a fixed head screw 117 may be used along with a locking insert 127 and a locking end cap 132 at the apex 125 of the scoliosis curve of the user's spinal column 118 to prevent migration of the elongated flexible member 102. Rotational head screws 116 with standard inserts 128 and standard end caps 130 are then used above and below the apex 125 to allow the elongated flexible member 102 to slide as needed post implantation and the screw head 120 of the rotational head screws to rotate as needed relative to the screw base 124, reducing forces and tension on the elongated flexible member 102, the screw head 120, the inserts, and the screw base 124 as the user's spinal column 118 extends, flexes and rotates.

[0019] As shown in FIGS. 4A-B and FIGS. 8A-B, the rotational head screws 116 comprise a screw head 120 with a slot (not shown) sized to accept the elongated flexible member 102 or a slot and space 122 sized to accept an insert 127 or 128 and a screw base (or screw shank) 124. During manufacture the screw head 120 is placed over the machine threaded portion of the screw base 124 and then a locking nut (or retaining nut) 126 is placed into the screw head 120 and threaded into position. The locking nut 126 locks into position on the screw head 120 and holds the screw head 120 on the screw base 124 but still allows it to rotate as needed, as the user moves. As shown in FIGS. 5A-B and FIGS. 8C-D, the fixed head screws 117 comprise a one piece screw 134 with a slot (not shown) sized to accept the elongated flexible member 102 or a slot and space 136 sized to accept an insert 127 or 128.

[0020] Typically, during the surgical procedure, after the screws are placed, an elongated flexible member 102 is positioned into an insert (or collet) (127 or 128) sized and shaped to accept the type of elongated flexible member chosen by the surgeon, some examples of which are 700, 702, 704, 706, 708, 710, 712 and 714. The assembly is then inserted into the space in the screw head 122 or 136 for retaining the elongated flexible member 102. The insert can be a standard insert 128 which fully encapsulates the elongated flexible member 102 while still allowing the elongated flexible member 102 to move or slide as needed post implantation, as the user moves. A standard end cap 130 is then inserted into the screw head to secure the standard insert 128 in place. Furthermore, instead of a standard insert 128, a locking insert 127 can be used which surrounds only the bottom and sides of the elongated flexible member 102. A locking end cap 132 is then inserted into the screw head until the inferior protrusion of the end cap compresses the elongated flexible member 102, fixing the member 102 in place. Further, for rotational head screws 116 the screw head 120 rotates as needed relative to the screw base 124, allowing the elongated flexible member 102 to more easily extend, flex and rotate, as the user's spinal column 118 extends, flexes and rotates reducing forces on the screw head 120, screw base 124, insert 127 or 128, and elongated flexible member 102. Additionally, the screws positioned at the superior and inferior tips of the elongated flexible member 102 may be larger (not shown) than standard screw heads to cover the end tips 110 and/or 112 of the flexible member 102.

[0021] Additionally, the orthopedic implant system 100 can be implanted laterally or posteriorly, depending on the wants and needs of a user. The orthopedic implant system 100 can be designed in multiple configurations, only some of which are shown in this application. For example, the plurality of vertebral body screws 104 can anchor a first elongated flexible member 102 along a lateral side of the user's spinal column 118. Then, a second plurality of vertebral body screws 104 can anchor a second elongated flexible member 102 to the opposing side of the user's spinal column 118 at the same or another curve location. Further, there is a possibility that the orthopedic implant system 100 can be removed after the user reaches skeletal maturity which provides the potential for a user to achieve a more normal degree of spinal function post removal.

[0022] FIG. 6 illustrates a driver device 600 that can be used to implant the rotational head screws 116, a prior art orthopedic hex head screwdriver (not shown) would be used for the fixed head screws 117.

[0023] In operation, a surgeon (not shown) would choose the specific size and/or shape of the elongated flexible band 102 that meets their users' needs and/or wants, depending on the size, flexibility, rotation, and/or curvature of the user's spinal column 118 the orthopedic implant system 100 will be used with. The surgeon would then determine if the orthopedic implant system 100 would be implanted laterally or posteriorly in the user. Once the position is determined, the surgeon would make an incision in the user and then would move soft tissue out of the approach area as needed. The surgeon would prepare the site for each vertebral body screw 104 and would insert as many vertebral body screws 104 as needed (i.e., rotational 116 and/or fixed 117 head screws), and spanning as many levels as necessary.

[0024] Once the vertebral body screws 104 are in place and secure, the surgeon will thread the chosen elongated flexible member 102 into the proper number of associated inserts 128 or 127. Then the surgeon, at the apex 125 of the user's scoliosis curve, secures (or fixes) the elongated flexible member 102 within a screw head using a locking insert 127 and a locking end cap 132, preventing migration of the elongated flexible member 102. The surgeon then uses an instrument (persuader) with a specially shaped tip (not shown) to straighten the spine. The base of the persuader is set on the head of the screw at the apex of the curve, the surgeon then places the end of the persuader under the head on the next screw and applies force, bringing the vertebral body in line with the apex vertebral body. The surgeon then sets the end cap (130 or 132). Once done, the surgeon moves to the next vertebral body screw 104 and repeats until all vertebral bodies, above and below the apex, are in line and end caps (130 or 132) set.

[0025] Thus, the elongated flexible member 102 is fixed in position at the apex 125 of the user's scoliosis curve, but can slide within the screw heads 120 or inserts 128 at the screw positions superior or inferior to the apex 125 of the user's scoliosis curve. Accordingly, the orthopedic implant system 100 allows the user to flex, extend, or rotate while at the same time correcting a scoliosis curve and/or restricting its growth. Furthermore, after the user reaches skeletal maturity, the orthopedic implant system 100 can potentially be removed, allowing a user to live a life that does not include an immobilized spine.

[0026] What has been described above includes examples of the claimed subject matter. It is, of course, not possible to describe every conceivable combination of components or methodologies for purposes of describing the claimed subject matter, but one of ordinary skill in the art may recognize that many further combinations and permutations of the claimed subject matter are possible. Accordingly, the claimed subject matter is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims. Furthermore, to the extent that the term "includes" is used in either the detailed description or the claims, such term is intended to be inclusive in a manner similar to the term "comprising" as "comprising" is interpreted when employed as a transitional word in a claim.

Claims

1. An orthopedic implant system for use in correcting or resisting the progression of scoliosis curves, comprising:

a plurality of vertebral body screws each comprising a screw base and a screw head with a slot or a slot for accepting an insert; and

an elongated flexible member engageable with the plurality of vertebral body screws;

wherein the plurality of vertebral body screws anchor the elongated flexible member to a user's spinal column; and

wherein the elongated flexible member is positioned within a slot in the screw head or via an insert.

2. The orthopedic implant system of claim 1, wherein the elongated flexible member is significantly larger in height than thickness and wherein the larger aspect of the elongated flexible member is implanted parallel to a long axis of the screw body and in same plane as plane of a user's scoliosis curve.

3. The orthopedic implant system of claim 1, wherein the plurality of vertebral body screws anchor the elongated flexible member along a lateral side of the user's spinal column.

4. The orthopedic implant system of claim 3, wherein a second plurality of vertebral body screws anchor a second elongated flexible member to an opposing side of the user's spinal column.

5. The orthopedic implant system of claim 1, wherein the plurality of vertebral body screws comprise rotational head screws and fixed head screws.

6. The orthopedic implant system of claim 5, wherein the elongated flexible member is fixed within a fixed head or rotational head screw at an apex of a scoliosis curve of the user's spinal column.

7. The orthopedic implant system of claim 6, wherein rotational or fixed head screws are inserted above and below the apex of the scoliosis curve.

8. The orthopedic implant system of claim 7, wherein the elongated flexible member positioned within the screw head or within an insert in the screw head can slide within the screw head or the insert within the screw head.

9. The orthopedic implant system of claim 8, wherein the screw head of the rotational head screws rotates as needed relative to the screw base reducing stresses on the elongated flexible member, screw head, and screw base.

10. The orthopedic implant system of claim 1, wherein the elongated flexible member extends past an end of last rotational head screw to allow for growth in the spinal column or an extended range of motion.

11. The orthopedic implant system of claim 2, wherein the elongated flexible member is manufactured of titanium, cobalt chromium, stainless steel, or other appropriate material.

Drawing